telsa coils ???

Andre Kesteloot
Sun, 11 Jan 1998 22:13:23 -0500

Ahaha,  Peter,

It is indeed interesting that you should mention the subject of Tesla
coils   :-)  (great minds etc.?)
Several of us here at AMRAD Galactic HQS are presently investigating
Tesla Coils and their relation to VLF.

One of us, George WB5OYP has actually seen in operation many of the units
illustrated on the web at
<> and even claims some
understanding of how the things work,  which, incidentally, is not as
evident as it would first appear.

Another one of us, Glenn KA0SA, has found at some recent hamfest ($5) a
high-voltage generator which was originally used to drive a
piezo-electric element, and was meant to heat parts of the body for
therapeutic purposes.  The gizmo looks very much like a classic Telsa
design : an oscillator (a horizontal output tube) a primary and a
secondary coil, and also a  _tertiary_  coil, just as in the original
Tesla designs. And the whole thing oscillates on ... 140 KHz.

Personally, I have just completed the building of a solid state exciter
that will be used to drive an  811 HF amplifier to try and determine how
we can create enough power at those frequencies. The advantage of using
tubes/valves for experimentation purposes is that, of course, tubes do
not object to high VSWR as violently as solid state devices do. (See for
instance my article "Tesla &c" in the December 1997 issue of the AMRAD

Now instead of having a very high impedance output (which would encourage
the production of  sparks), how do we arrange to couple those things to a
rather low-impedance item, such as an antenna?


André Kesteloot  N4ICK

Peter Martinez wrote:

> On the subject of helical antennas for VLF, I wonder if anyone
> knows anything about Tesla coils?